diff --git a/dlls/kernel32/tests/thread.c b/dlls/kernel32/tests/thread.c
index 0f3564f4bfc..33797d84892 100644
--- a/dlls/kernel32/tests/thread.c
+++ b/dlls/kernel32/tests/thread.c
@@ -287,7 +287,6 @@ static DWORD WINAPI thread_actctx_func(void *p)
     cur = (void*)0xdeadbeef;
     ret = pGetCurrentActCtx(&cur);
     ok(ret, "thread GetCurrentActCtx failed, %u\n", GetLastError());
-todo_wine
     ok(cur == param->handle, "got %p, expected %p\n", cur, param->handle);
     param->thread_context = cur;
 
@@ -1550,6 +1549,17 @@ static void test_thread_actctx(void)
     ok(b, "GetCurentActCtx failed: %u\n", GetLastError());
     ok(handle == 0, "active context %p\n", handle);
 
+    /* without active context */
+    param.thread_context = (void*)0xdeadbeef;
+    param.handle = NULL;
+    thread = CreateThread(NULL, 0, thread_actctx_func, &param, 0, &tid);
+    ok(thread != NULL, "failed, got %u\n", GetLastError());
+
+    ret = WaitForSingleObject(thread, 1000);
+    ok(ret == WAIT_OBJECT_0, "wait timeout\n");
+    ok(param.thread_context == NULL, "got wrong thread context %p\n", param.thread_context);
+    CloseHandle(thread);
+
     b = pActivateActCtx(context, &cookie);
     ok(b, "activation failed: %u\n", GetLastError());
 
@@ -1568,7 +1578,6 @@ static void test_thread_actctx(void)
 
     ret = WaitForSingleObject(thread, 1000);
     ok(ret == WAIT_OBJECT_0, "wait timeout\n");
-todo_wine
     ok(param.thread_context == context, "got wrong thread context %p, %p\n", param.thread_context, context);
     CloseHandle(thread);
 
@@ -1579,7 +1588,6 @@ todo_wine
 
     ret = WaitForSingleObject(thread, 1000);
     ok(ret == WAIT_OBJECT_0, "wait timeout\n");
-todo_wine
     ok(param.thread_context == context, "got wrong thread context %p, %p\n", param.thread_context, context);
     CloseHandle(thread);
 
diff --git a/dlls/ntdll/thread.c b/dlls/ntdll/thread.c
index 703e83cf1be..9c34c0c2603 100644
--- a/dlls/ntdll/thread.c
+++ b/dlls/ntdll/thread.c
@@ -432,7 +432,7 @@ NTSTATUS WINAPI RtlCreateUserThread( HANDLE process, const SECURITY_DESCRIPTOR *
     pthread_attr_t attr;
     struct ntdll_thread_data *thread_data;
     struct startup_info *info = NULL;
-    HANDLE handle = 0;
+    HANDLE handle = 0, actctx = 0;
     TEB *teb = NULL;
     DWORD tid = 0;
     int request_pipe[2];
@@ -497,6 +497,21 @@ NTSTATUS WINAPI RtlCreateUserThread( HANDLE process, const SECURITY_DESCRIPTOR *
     teb->StaticUnicodeString.Buffer        = teb->StaticUnicodeBuffer;
     teb->StaticUnicodeString.MaximumLength = sizeof(teb->StaticUnicodeBuffer);
 
+    /* create default activation context frame for new thread */
+    RtlGetActiveActivationContext(&actctx);
+    if (actctx)
+    {
+        RTL_ACTIVATION_CONTEXT_STACK_FRAME *frame;
+
+        frame = RtlAllocateHeap(GetProcessHeap(), 0, sizeof(*frame));
+        frame->Previous = NULL;
+        frame->ActivationContext = actctx;
+        frame->Flags = 0;
+        teb->ActivationContextStack.ActiveFrame = frame;
+
+        RtlAddRefActivationContext(actctx);
+    }
+
     info = (struct startup_info *)(teb + 1);
     info->teb         = teb;
     info->entry_point = start;